プレビューのスクリーンショット

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it does disclose the output format (PNG). However it says nothing about scope of 'current screen', whether it requires the window to be open/focused, or latency/cost considerations for a capture operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with zero waste: the operation is front-loaded, followed immediately by the trigger condition. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter, no-output-schema tool the description covers what it does and when to use it. The one real gap is disambiguation from jizura_snapshot, which an agent in this family of tools would benefit from.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is nothing for the description to compensate for; the baseline of 4 applies. No parameter-related meaning is missing.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete verb and resource: captures the current screen as a PNG image. That is specific and actionable, but it does not distinguish itself from the similarly named sibling jizura_snapshot, which an agent could reasonably confuse with a screen-capture operation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit usage condition: use it when you want to visually confirm the arrangement result. That is clear context for when to call it, though it names no exclusions or alternatives (e.g. snapshot vs screenshot) to disambiguate the sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.